The multiple-hit pathogenesis of non-alcoholic fatty liver disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent and represents a growing challenge in terms of prevention and treatment. Despite its high prevalence, only a small minority of affected patients develops inflammation and subsequently fibrosis and chronic liver disease, while most of them only exhibit simple steatosis. In this context, the full understanding of the mechanisms underlying the development of NAFLD and non-alcoholic steatohepatitis (NASH) is of extreme importance; despite advances in this field, knowledge on the pathogenesis of NAFLD is still incomplete. The 'two-hit' hypothesis is now obsolete, as it is inadequate to explain the several molecular and metabolic changes that take place in NAFLD. The "multiple hit" hypothesis considers multiple insults acting together on genetically predisposed subjects to induce NAFLD and provides a more accurate explanation of NAFLD pathogenesis. Such hits include insulin resistance, hormones secreted from the adipose tissue, nutritional factors, gut microbiota and genetic and epigenetic factors. In this article, we review the factors that form this hypothesis

Zinc Transporter 8 Antibodies Complement GAD and IA-2 Antibodies in the Identification and Characterization of Adult-Onset Autoimmune Diabetes: Non Insulin Requiring Autoimmune Diabetes (NIRAD) 4

OBJECTIVE: Zinc transporter 8 (ZnT8) is an islet beta-cell secretory granule membrane protein recently identified as an autoantibody antigen in type 1 diabetes. The aim of this study was to determine the prevalence and role of antibodies to ZnT8 (ZnT8As) in adult-onset diabetes. RESEARCH DESIGN AND METHODS: ZnT8As were measured by a radioimmunoprecipitation assay using recombinant ZnT8 COOH-terminal or NH(2)-terminal proteins in 193 patients with adult-onset autoimmune diabetes having antibodies to either GAD (GADAs) or IA-2 (IA-2As) and in 1,056 antibody-negative patients with type 2 diabetes from the Non Insulin Requiring Autoimmune Diabetes (NIRAD) study. RESULTS: ZnT8As-COOH were detected in 18.6% patients with autoimmune diabetes and 1.4% with type 2 diabetes. ZnT8As-NH(2) were rare. ZnT8As were associated with younger age and a high GADA titer. The use of GADAs, IA-2As, and ZnT8As in combination allowed a stratification of clinical phenotype, with younger age of onset of diabetes and characteristics of more severe insulin deficiency (higher fasting glucose and A1C, lower BMI, total cholesterol, and triglycerides) in patients with all three markers, with progressive attenuation in patients with two, one, and no antibodies (all P(trend) < 0.001). Autoantibody titers, association with high-risk HLA genotypes, and prevalence of thyroid peroxidase antibodies followed the same trend (all P < 0.001). CONCLUSIONS: ZnT8As are detectable in a proportion of patients with adult-onset autoimmune diabetes and seem to be a valuable marker to differentiate clinical phenotypes

Use of DPP4 inhibitors in Italy does not correlate with diabetes prevalence among COVID-19 deaths

In a nationwide study of 3,818 charts from patients with fatal COVID-19, we found that geographical differences in Dipeptidyl peptidase 4 (DPP4) inhibitors use did not correlate with diabetes prevalence among COVID-19 deaths, thus not supporting the hypothesis of a clinically relevant involvement of DPP4 in COVID-19 development and progression

Pasta consumption and connected dietary habits: Associations with glucose control, adiposity measures, and cardiovascular risk factors in people with type 2 diabetes—TOSCA.IT study

Background: Pasta is a refined carbohydrate with a low glycemic index. Whether pasta shares the metabolic advantages of other low glycemic index foods has not really been investigated. The aim of this study is to document, in people with type-2 diabetes, the consumption of pasta, the connected dietary habits, and the association with glucose control, measures of adiposity, and major cardiovascular risk factors. Methods: We studied 2562 participants. The dietary habits were assessed with the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire. Sex-specific quartiles of pasta consumption were created in order to explore the study aims. Results: A higher pasta consumption was associated with a lower intake of proteins, total and saturated fat, cholesterol, added sugar, and fiber. Glucose control, body mass index, prevalence of obesity, and visceral obesity were not significantly different across the quartiles of pasta intake. No relation was found with LDL cholesterol and triglycerides, but there was an inverse relation with HDL-cholesterol. Systolic blood pressure increased with pasta consumption; but this relation was not confirmed after correction for confounders. Conclusions: In people with type-2 diabetes, the consumption of pasta, within the limits recommended for total carbohydrates intake, is not associated with worsening of glucose control, measures of adiposity, and major cardiovascular risk factors

Dietary Fat, Sugar Consumption, and Cardiorespiratory Fitness in Patients With Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is associated with obesity and, indirectly, with unhealthy diet. The role of dietary components in HFpEF is, however, largely unknown. In this study, the authors showed that in obese HFpEF patients, consumption of unsaturated fatty acids (UFA), was associated with better cardiorespiratory fitness, and UFA consumption correlated with better diastolic function and with greater fat-free mass. Similarly, mice fed with a high-fat diet rich in UFA and low in sugars had preserved myocardial function and reduced weight gain. Randomized clinical trials increasing dietary UFA consumption and reducing sugar consumption are warranted to confirm and expand our findings

Transaminase abnormalities and adaptations of the liver lobule manifest at specific cut-offs of steatosis

There is little documented evidence suggesting that liver fat is responsible for liver injury in the absence of other disease processes. We investigated the relationships between liver fat, aminotransferases and hepatic architecture in liver biopsies with simple steatosis. We identified 136 biopsies with simple steatosis from the Royal Free Hospital Archives with both clinical data and sufficient material. Digital image analysis was employed to measure fat proportionate area (mFPA). Hepatocyte area (HA) and lobule radius (LR) were also measured. There were significant increases in ALT (p &lt; 0.001) and AST (p = 0.013) with increased fat content and evidence to suggest both 5% and 20% mFPA as a cut-off for raised ALT. In liver with increased fat content there were significant increases in HA (p &lt; 0.001). LR also increased as mFPA increased to 10% (p &lt; 0.001), at which point the lobule ceased to expand further and was counterbalanced with a decrease in the number of hepatocytes per lobule (p = 0.029). Consequently there are mechanisms of adaption in the liver architecture to accommodate the accumulation of fat and these are accompanied by significant increases in transaminases. These results support the generally accepted cut-off of 5% fat for steatosis and indicate 20% as a threshold of more severe liver injury

Collagen proportionate area predicts long-term mortality in patients with alcoholic hepatitis

Background and aims: There are several short-term prognostic scores for alcoholic hepatitis (AH) that combine demographical and biochemical parameters. The extent of liver fibrosis may also be relevant to the prognosis of AH with potential added value. We evaluated collagen proportionate area (CPA) as a predictor of short and long-term mortality in AH. Methods: We retrospectively included patients with biopsy-verified AH. Clinical, laboratory and outcome data were collected. CPA and five AH scores were calculated: Maddrey's DF, MELD, GAHS, ABIC, and the Lille Model. Predictors of short and long-term all-cause mortality were assessed using Cox regression analysis. Results: We included 140 patients with AH. In total, 67 (48%) patients died after a median follow-up of 66 (IQR 102) months, with 17 (12%) dying within the first 90-days. CPA was not a predictor of 90-days mortality and had no additional value to the prognostic AH scores on short-term mortality. However, CPA predicted long-term mortality independently of prognostic AH scores. Importantly, CPA and abstinence from alcohol were independent predictors of long-term mortality in patients alive 90 days after the biopsy. Conclusion: CPA predicts long-term mortality in patients with AH independently of abstinence from alcohol but has no prognostic value on short-term mortality

Collagen proportionate area predicts long-term mortality in patients with alcoholic hepatitis

Background and aims: There are several short-term prognostic scores for alcoholic hepatitis (AH) that combine demographical and biochemical parameters. The extent of liver fibrosis may also be relevant to the prognosis of AH with potential added value. We evaluated collagen proportionate area (CPA) as a predictor of short and long-term mortality in AH. Methods: We retrospectively included patients with biopsy-verified AH. Clinical, laboratory and outcome data were collected. CPA and five AH scores were calculated: Maddrey's DF, MELD, GAHS, ABIC, and the Lille Model. Predictors of short and long-term all-cause mortality were assessed using Cox regression analysis. Results: We included 140 patients with AH. In total, 67 (48%) patients died after a median follow-up of 66 (IQR 102) months, with 17 (12%) dying within the first 90-days. CPA was not a predictor of 90-days mortality and had no additional value to the prognostic AH scores on short-term mortality. However, CPA predicted long-term mortality independently of prognostic AH scores. Importantly, CPA and abstinence from alcohol were independent predictors of long-term mortality in patients alive 90 days after the biopsy. Conclusion: CPA predicts long-term mortality in patients with AH independently of abstinence from alcohol but has no prognostic value on short-term mortality